Magnetic sensors are capable of detecting magnetic fields or changes of magnetic fields. Magnetoresistive effects used in magnetoresistive sensors include but are not limited to GMR (Giant Magnetoresistance), AMR (Anisotropic Magnetoresistance), TMR (Magneto Tunnel Effect), CMR (Colossal Magnetoresistance). Another type of magnetic sensors is based on the Hall effect. Magnetic sensors are used, for example, to detect the position of moving or rotating objects, the speed or rotational speed of rotating objects, etc. They may be used in automotive applications.
In some applications such as, for example, for the detection of a rotational speed of an object, a bias magnetic field is applied to the magnetic sensor in order to avoid saturation. Typical examples include, for example, a back bias magnet arrangement. In the back bias magnet arrangement, the magnetic sensor is provided between the object to be sensed and the bias magnet.